Belt tension systems are found in many different types of machinery including, for example, chippers and grinders. Chippers are used to reduce branches, trees, brush, and other bulk wood products into small chips. A chipper typically includes a feed system for controlling the feed rate of wood products into the chipper, a chipping mechanism, a drive system for powering the feed system and the chipping mechanism, and a discharge chute.
The chipping mechanism is commonly a large drum that includes blades thereon which is driven by a belt. The belt rotates the drum, enabling the drum to grind, flail, cut, or otherwise reduce the material fed into the chipper into small chips. The proper tension in the belt between the motor and the drum can be difficult to maintain as the belts tend to stretch and contract over time or even during use. Accordingly, there is a need in the art for an improved belt tension system.
Accelerating chipper drums and other cutting tools from a stopped position to maximum speed can be a challenge because the drums and other cutting/grinding tools are relatively large and heavy. If the belt is fully engaged between the output shaft and the drum during start up, the engine can be overloaded. To avoid overloading the engine in the start up process, typically a clutch is used to interface between the engine and the wheel that drives the belt. The clutch typically mounts adjacent the output shaft of the engine which is typically perpendicular to the length of the chipper or grinder frame. Accordingly, the inclusion of the clutch constrains how narrow the machine can be constructed. Also, since the clutch mechanism is lighter than the engine, the inclusion of the clutch typically undesirably shifts the center of gravity of the machine off to one side of the frame. A belt tension arrangement that could eliminate the need for a clutch is desirable.